Adjustable finger depth control for bowling balls



Sept. 7, 1965 P. T. BLOOD. 3,204,960

ADJUSTABLE FINGER DEPTH CONTROL FOR BOWLING BALLS Filed June 6, 1962 INVENTOR. PERZEY 7. 5:000

ATTOR/VFY United States Patent 3,204,960 ADJUSTABLE FINGER DEPTH CONTROL FOR BOWLING BALLS Perley T. Blood, 6811 Delta Drive, No. 216, El Paso, Tex. Filed June 6, 1962, Ser. No. 200,557 1 Claim. (Cl. 273-63) This invention relates to the finger and thumb holes which provide the grip on a bowling ball. For uniformly accurate bowling, it is, of course, essential that a ball be selected having the thumb and finger holes of a size and spacing to fit the hand of the user. The thumb hole should be of a size to prevent binding friction on the thumb when inserted full depth so that the thumb may move freely in and out and the finger holes should be of a size to similarly allow free in and out movement. The finger holes should be spaced from the thumb hole so that the second joints of the two middle fingers will extend at least a quarter of an inch over the near edges of the finger holes.

However, it is possible to obtain non-uniform results even though the holes meet all of the above specifications. For instance, the bowler may unconsciously and occasionally vary the distance his thumb is inserted in the thumb hole. This results in a variation of the position of the second joints of the fingers relative to the finger holes causing a variation in the center of gravity relative to the hand and a variation in the release timing of the ball. Similarly, a variation in the distance the fingers are inserted will unconsciously occur causing nonuniform and inaccurate results.

The principal object of this invention is to provide a depth control for the thumb and finger holes of a bowling ball which can be accurately preset to indicate when the fingers and thumb have been inserted to depths preselected for best results-the proper depths for producing the greatest accuracy for the ball owner.

Another object is to provide a depth control of the above type which can be quickly and economically applied to present bowling balls and which can be adjusted under actual bowling conditions to obtain optimum results for a given bowler and which when once adjusted will permanently retain its preadjustment.

A further object is to provide a thumb and finger depth limiting device of the above nature which will form an adjustable sub-bottom in a finger or thumb grip hole in a bowling ball and which when once adjusted will automatically position the thumb and fingers in the perfect grip position without requiring any attention on the part of the bowler.

A still further object is to provide a depth limiting device for bowling balls which, when once installed and balanced in the finger and thumb holes of a ball, cannot be removed without completely destroying the device so as to prevent interference with the balance of the ball.

Other objects and advantages reside in the detail construction of the invention, which is designed for simplicity, economy, and efiiciency. These will become more apparent from the following description.

In the following detailed description of the invention, reference is made to the accompanying drawing which forms a part hereof. Like numerals refer to like parts in all views of the drawing and throughout the description.

FIG. 1 is a fragmentary View of a hand suspended bowling ball partially broken away to show the invention in place therein;

FIG. 2 is a side elevational view of a stop element as employed in this invention;

FIG. 3 is a top view of the stop element of FIG. 2;

FIG. 4 is a side view of the stop element shown partially in section, the sectional portion being taken on the line 4-4, FIG. 3; and

FIG. 5 illustrates a tool for installing and adjusting the stop element in a bowling ball.

In the drawing, a conventional bowling ball is indicated at 10 with its thumb hole at 12 and a finger hole at 13. Some such balls are drilled with two holes, a finger hole and a thumb hole. Others are drilled with three holes to be gripped with thumb and two fingers. The latter are in the majority. This invention applies to either type of ball however.

Broadly, the invention comprises an adjustable hole bottom element to be positioned in the grip holes 12 and 13 of the ball 10 to prevent the thumb and fingers from being inserted beyond a preselected depth.

The bottom element is applied to 'the ball by drilling an axially-directed shank hole 22 in the bottom of each of the finger and thumb holes then tapping the hole to form threads therein corresponding to the threads on a shank to be later described. The entrances to the threaded shank holes 22 are preferably counterbored as indicated at 19.

The adjustable bottom element, as illustrated, comprises an elongated shank 14 having an enlarged circular head 15. The head is provided with a smooth concave upper surface 16 in which two oppositely wrench sockets 17 are indented. The diameter of the head is slightly less than the diameter of the finger and thumb holes in the bowling ball. The extremities of the shank 14 are slightly enlarged and the enlargements are threaded as shown at 18 so that they may be threaded into the axially-directed shank holes in the ball. The counterbores 19 assist in aligning the threaded shanks with the threaded shank holes 22, and the threaded shank threads 18 will fit frictionally tight in the shank holes to maintain any desired presetting. The shanks may be rotated by any desired tool. As illustrated, the rotation is accomplished by means of a spanner wrench 20, as shown in FIG. 5, having two projecting teeth 21 of a size and spacing to enter the wrench sockets 17.

The depth to which the bottom elements are set is determined by trial and error. For intsance, the threaded shanks are threaded inward until they are beyond the reach of the fingers and thumb. The thumb and finger are then repeatedly trial. inserted in correct position with the second finger joints engaging the near edge of the finger holes and with the thumb in its fully inserted comfortable position.

After each trial insertion, the bottom elements are threaded outwardly until a point is reached when the extremities of the fingers and thumb will rest lightly against the concave upper surfaces 16 of their respective bottom elements.

Actual bowling trials are now made and further relative adjustments between the depths of the thumb and finger holes may be made until a grip is found of optimum efficiency. No further adjustment need be made as long as that ball is used by the bowler to whom it was adjusted. He can always be certain that when his thumb and fingers are inserted as far as they will go, his grip is in the proper position for the best results.

To comply with conventional bowling requirements it is essential that the depth limiting device contain no metallic elements and that when once installed it be nonremovable so as to prevent counterweights and other illegal equipment from being placed in the grip holes.

The objection to metal is met by forming all of the depth-limiting elements of suitable plastic material.

The objection to removal is met with the use of a locking element 23 of nylon or similar relatively stiff flexible Patented Sept. 7, 1965 material which projects oppositely outward from the shank to a diameter in excess of the diameter of the thumb and finger holes of the ball. Prior to installation, an internal locking groove 24 is cut circumferentially around each grip hole adjacent the bottom thereof. The enlarged threaded extremity 18 of the shank is forcibly threaded into the tapered threaded opening in the locking element 23 to expand the same. The locking element is then forced into the grip hole of the ball, the extremities of the locking element flexing upwardly as they enter, until the extremities of the locking element snap into the locking groove 24 Where they will be maintained by the natural tendency of the locking element to straighten and expand. The shank is now forcibly threaded through the tapered hole in the locking element, after which the latter hole will contract, and into the shank hole 22 in the ball. It cannot thereafter be pulled from place without completely breaking and destroying the locking element.

The counterbores 19 prevent the threads 18 on the shanks from engaging the threads in the shank holes until the threaded enlargements on the shanks have passed completely through the locking elements 23. Thus, the shanks can rotate freely before they enter and after they leave the threads in the shank holes. This prevents any pressure from being exerted upward against the locking elements 23 by unscrewing the shanks. Therefore, once inserted, the locking elements and the depth limiting devices cannot be removed.

While a specific form of the improvement has been described and illustrated herein, it is to be understood that the same may be varied within the scope of the appended claim, without departing from the spirit of the invention.

Having thus described the invention, what is claimed and desired to be secured by Letters Patent is:

Means for presetting the depth to which the thumb and fingers of a bowler may be inserted in a grip hole of a bowling ball comprising: an axially directed, threaded shank hole in the bottom of said grip hole; an annular locking groove in the internal wall of said hole; an elongated, resiliently and downwardly flexed locking element of greater length than the diameter of said hole extending diametrically of the latter, the extremities of said locking element being positioned in said locking groove and being urged diametrically outward in said locking groove by the resilient tendency of said flexed locking element to resume a straight position; a rotatable elongated shank extending downwardly through a guide hole in the medial portion of said locking element; a threaded lower extremity on said shank of larger diameter than said guide hole to resist upward withdrawal of said shank through said guide hole, said threaded lower extremity being threaded into the threads of said shank hole; and an enlarged circular head on the upper extremity of said shank of slightly less diameter than said grip hole.

References Cited by the Examiner UNITED STATES PATENTS 2,709,470 5/55 Knohl l5 l-69 X 2,936,177 5/60 Dietz 273-63 3,039,774 6/62 Gerlack 273-63 3,137,505 6/64 Coppola 27363 RICHARD C. PINKHAM, Primary Examiner.

LEONARD W. VARNER, Examiner. 

